He testified in Congress shortly after the incident, and claimed that it was the stupid video. Now there’s reports that he just testified in Congress that it was a terrorist attack and he knew it all along. Two different stories. Both under oath. That’s disturbing to me.

Lying to Congress while not under oath, nevertheless, might well be a crime:

18 U.S.C. § 1001 : US Code - Section 1001

(a) Except as otherwise provided in this section, whoever, in any
matter within the jurisdiction of the executive, legislative, or
judicial branch of the Government of the United States, knowingly
and willfully -
(1) falsifies, conceals, or covers up by any trick, scheme, or
device a material fact;
(2) makes any materially false, fictitious, or fraudulent
statement or representation; or
(3) makes or uses any false writing or document knowing the
same to contain any materially false, fictitious, or fraudulent
statement or entry;
shall be fined under this title, imprisoned not more than 5 years
or, if the offense involves international or domestic terrorism (as
defined in section 2331), imprisoned not more than 8 years, or
both.
(b) Subsection (a) does not apply to a party to a judicial
proceeding, or that party’s counsel, for statements,
representations, writings or documents submitted by such party or
counsel to a judge or magistrate in that proceeding.
(c) With respect to any matter within the jurisdiction of the
legislative branch, subsection (a) shall apply only to -
(1) administrative matters, including a claim for payment, a
matter related to the procurement of property or services,
personnel or employment practices, or support services, or a
document required by law, rule, or regulation to be submitted to
the Congress or any office or officer within the legislative
branch; or
(2) any investigation or review, conducted pursuant to the
authority of any committee, subcommittee, commission or office of
the Congress, consistent with applicable rules of the House or
Senate.